This application claims priority of Korea patent Application No. 2000-86946, filed on Dec. 30, 2000.
(a) Field of the Invention
The present invention relates to a method for controlling a charging state of a battery for an electric vehicle, and more particularly to a method for controlling a charging state of a battery of an electric vehicle for diagnosing a failure possibility and for compensating a charging state of the battery, by detecting an operating state of the battery while driving a vehicle that is equipped with a rechargeable battery.
(b) Description of the Related Art
Generally, an electric vehicle and a hybrid electric vehicle are provided with a rechargeable battery that is to be repeatedly charged and discharged.
FIG. 1 illustrates a schematic block diagram of an electric vehicle.
As shown in FIG. 1, an engine 14 generates driving power by using fuel, and the driving power rotates a generator 15. The generator 15 converts the relational power of the engine to electric power, a battery 11 is charged by the electric power, and a motor 13 is driven.
The electric power generated by the generator 15 is charged into the battery after being converted into direct current through a rectifier. The electric power that is generated by the generator 15 or that is outputted by discharge of the battery is delivered to the motor 13 based on control of a motor controller 12, and the vehicle is driven by the rotary power of the motor that is delivered to wheels through a power transmission gear.
A controller 16 detects a state of the motor 13, battery 11, and engine 14, and controls an operating state of the motor controller 12 and generator 15 based on a predetermined pattern.
The controller 16 determines an error condition of the battery when a battery voltage is more than a predetermined critical value or less than another predetermined critical value, while charging or discharging.
Furthermore, the controller 16 determines a battery failure when a voltage difference between a particular battery module and the average voltage of all battery modules exceeds a predetermined value, while charging and discharging.
However, as described above, since the prior art does not determine a battery state but determines only whether the battery is in a normal state or not, it is impossible to compensate for a faulty battery and to determine a cause thereof.
The present invention provides a method for controlling a charging state, for diagnosing a failure possibility and for compensating for a charging state of a faulty battery of an electric vehicle by detecting an operating state of the battery while driving a vehicle that is equipped with a rechargeable battery.
To achieve the above, the present invention provides a method for controlling the charging state of a battery of an electric vehicle, comprising:
collecting data of the charging state of each battery module and individually storing the collected data by control means, during a charging mode of the battery of a vehicle that is equipped with a rechargeable battery;
collecting data of a charging state of each battery module and individually storing the collected data by control means, in a driving mode of the vehicle; and wherein
a data row allotted to each module from storage is detected,
displaying a high state for a battery charging state at a predetermined area of the data row corresponding to a battery module having a high voltage in driving mode and in charging mode;
displaying a normal or good state for a battery charging state at the predetermined range of the data row corresponding to a battery module having a high voltage in driving mode and a low voltage in charging mode;
displaying a low state for a battery charging state at the predetermined range of the data row corresponding to a battery module having a low voltage in driving mode and in charging mode, and overcharging the corresponding battery by a predetermined value during the next charging; and
displaying a fail possibility state for a battery charging state at the predetermined range of the data row corresponding to a battery module having a low voltage in driving mode and a high voltage in charging mode, and warning of maintenance service of the corresponding battery during the next charging or discharging.